Terrain

Explained in Terrain.

class Terrain

import { Terrain } from '@driftengine/terrain';

Constructor

`new`

constructor(options: HeightfieldOptions)

Parameter	Type	Description
`options`	`HeightfieldOptions`

Properties

Name	Type	Description
`width`readonly	`number`
`depth`readonly	`number`
`spacingM`readonly	`number`
`origin`readonly	`Float32Array<ArrayBuffer>`	World position of sample `(0, 0)`, copied because a caller reuses its vectors.
`heights`readonly	`Float32Array`	The samples, copied for the same reason and because this is read every frame.

Accessors

Name	Type	Description
`extentX`get	`number`	How far the field reaches along x, metres. One less cell than it has samples.
`extentZ`get	`number`

Methods

`sample`

sample(ix: number, iz: number): number

One sample, by grid index, clamped to the field rather than wrapping or answering NaN.

Parameter	Type	Description
`ix`	`number`
`iz`	`number`

`heightAt`

heightAt(x: number, z: number): number

The height of the drawn surface at a world position.

Parameter	Type	Description
`x`	`number`
`z`	`number`

The triangle and not the bilinear patch, for the reason at the top of this file. The cell is split along its a-c diagonal — from the sample at (ix, iz) to the one at (ix + 1, iz + 1) — and heightfieldPatch emits exactly that split, so the two cannot disagree about where the ground is.

Clamped outside the field. A world has an edge and a query past it should answer the edge rather than extrapolate a slope into a place that has no samples.

`normalAt`

normalAt(x: number, z: number, out: Float32Array): Float32Array

The surface normal at a world position, as a central difference over the samples.

Parameter	Type	Description
`x`	`number`
`z`	`number`
`out`	`Float32Array`

Continuous across every cell boundary, which is what stops two patches shading differently along the edge they share — the failure that reads as a crack in geometry that has none.